Rifle-sighting telescope



July 9, 1940. I F. L. KYOLLMORGYEN RIFLE SIGHTING TELESCOPE.

Filed March 8, 1938 INVENT OR.

, ATTORNEY.

Patented July 9,

UNITED STAT PATENT OFFICE I 7 2,201,124 7 ms-smn'rma rut-sworn mane.-

Kollmorlen, Mountain Lakes,

J No In Application mm a, ma, Serlnl no. new

H vzczn'elms.(onus-4:!) The present invention, relates to telescopes.

' this distance might have been suiilcient in some" and, to a. rifle-sighting teleguns orriiies, in most guns the telescope had to ope.

high or oil-set mounting in order the bolt action or some o more particularly,

have a relatively of novel and improved' charscteri ther opere ting luminous side of the eye lens.' This-luminous circle is the barrel sndwould have rendered the mounting and less liab substantial known as the exit pupilof the telescope,

le to displacement. 11 known in the art a and. more the pupil of the observer's eye must be brought Although this situation was we into coincidence with the exit pupil. toensble him and from time to time various suggestions and the eye distance. of these various to see the. entire field ot viewat one time. 11. pro the equivalent focal len eye piece is none,

posals were made to increase gth'oi the as far as I am aware,

between lesco'pe obsuggestions and proposals was satisfactory and and could provide on eye 3 greater than 4 denoted by 1"; the distance i active and eye piece by A, and the eye piece is successful 15 assumed to he a mm lens, then the distance inches.

is found by e I have discovered thet the outstanding problem may be solved in s r emsrkshly simple v of the exit pupil from the eye lens;

the equation Itis an object of the presentinvention to provide a novel and improved riii which is e-sighting telescope free from the disadvantages and 111- The quantities in the formula are given in absozs ee W e. M v mwmm wwmmm M w t m mmw enmwwm m an mm m mm m mm m m mm W mmmwmmwmmmmmwm when w mmfifo n i. m Wmmmm wmm mm emm m e mmwmmm wm m mmwmmmx ew ?with Wm mememmmfimmemwmm m w mums mwmmwm m mw m m m m mmw WW mega mwmmmmm e M WWMWM MW WMM mmmm mmmmmm m 7.. w mmmmdmm v m mmmm m m s, lnmfi m mmmmfim t w wmwm wmmm mmmmmm mwM MW m smwflmmm H m m m mm wmw m mmmm mmmwm wmmm wm e mmwmmm mmmmtmmmmm hm? Y, a n

u-otherwisejmtisi'sctorroptlcelresults. o

'lens I and an eye lens! Other and further objects and advantages will become apparent from the following description taken in conjunction with the accompanying drawing, in which:

Fig. 1 illustrates adiagrammatic view of the lens system employed in a conventional riflesighting telescope;

Fig. 2 depicts a diagrammatic view of a complete lens system embodying the principles of the present invention;

Fig. 3 is a side elevational view of a rifle with my new rifle-sighting telescope mounted thereon; and

Fig. 4 shows a front elevatlonal view of the rifle and telescope illustrated in Fig. 3.

Broadlystated, my invention makes use of the optical principle of projecting the image of an opening instead of the ,opening itself. According to the principles of my invention, an increased eye distance is obtaned by inserting a negative lens between the erector system and the eye lens, and near the second focus of the erector lens. This negative lens forms a virtual image of the erector lens located near the eyepiece lens and this image, being nearer to the eye lens, will in turn be imaged by the eye lens at a greater distance from it than'the erector lens itself would be.

The proper focal length, shape and position of the negative lens depend on the characteristics of the entire rifle sight, If the negative lens were placed exactly in the second focus of the system objective plus erector, it" would lengthen the eye. distance without changing the field of view or the power of the telescope. If placed between the erector and the said focal point, it would also increase magnification and reduce "field; if placed nearer the eye piece, it would lower the magniflcation and would to ,a certain extent increase the field. It will, therefore, be obvious to those skilled in the art that the opticalxsystem of the invention has a large number of possibilities but as long as a lens negative in character is incorporated in the optical system between erector and eyepiece, it will provide an increase in eye distance. Thus, a riflesighting telescope embodying the principles of the present invention may be mounted on a rifle barrel in such a position that it will clear the bolt action, even if mounted directly on the rifle barrel.

Referring now, more particularly, to Fig. 1 of the drawing, a diagrammatic view of the lens system employed in a conventional rifle-sighting telescope is illustrated. Essentially, an objective are provided with an erector lens or system I located therebetween for obtaining an erect image. -A sighting mark or reticule I is provided in the, focus of the objective lens I. Reference character 5 denotes the-second focus of the erecting system, and reference character I the eye of the observer, which it at a distance I from the eye lens. Distance I is known as the "eye distance" and .is the distance at which an image is formed by the eye-piece of either the objective or the erecting lenses of the telescope. This image is known as the exit pup of.the telescope and is the only position from which. the eye of the observer can see the entire fleld of view. The exit pupilappears as a small, bright circle when looking at the telescope from a distance.

For practical reasons, it has so far been found impossible to increase the eye distance, i. e., the distance of the exit pupil from the eyepiece lens,

'beyond 4" without making the telescope too long and bulky. The principles of the present invention make it possible to increase the eye distance to 5", and even more, without 'unduly increasing the length of the telescope, and also make is possible to increase or decrease the magniflcation' at will without changing the dimenv.sions of the telescope or of the lenses.

The principles and the operation of my improved rifle-sighting telescope will be best understood from Fig. 2 in which the optical system of a preferredembodiment of the invention is illustrated. The optical system includes some of the conventional elements of prior rifle-sighting telescopes such as objective lens ll, eye lens I2 and erector lens or system It. .As in all conventional rifle-sighting telescopes, a sighting mark it is provided in the focus of the objective lens ll. However, instead of imaging the erector system directly through the eyepiece lens, a negative lens I9 is inserted between erecting system it and eye lens i2, and near the second focus 20 of the erector lens. Negative lens I! forms a virtual image of the erector lens located near the eyepiece lens, and this image being nearer to the eye lens will in turn be imaged by the eye lens at'a greater distance therefrom than the erector lens would be itself. In other words, eye distance II corresponding to the distance of the observer's eye I 8 from the eye lens II, will be considerably greater than it was possible heretofore, as'those skilled in the art will readily understand. In accordance with the strength and the position of negative lens ll, eye distance l1 may be increased or decreased within relatively wide limits. For example, if this negative lens were placed exactly in the second focus 20 of the erector system, it will not affect the niagnlflcation or' the fleld of the telescope at all.

If the negative lens were placed between the second focus and the erector lens, it will increase the magnification and decrease the fleld', while, if the negative lens were placed between the second focus of the erectorlens and the eye lens, it will decrease the magniflcation and increase the field.

The completely assembled rifle-sighting telescope embodying the. invention is illustrated in Figs. 3 and 4 as mounted on a rifle in operative position. The complete optical system of the telescope is mounted in a tube 2! constituted of a metal such as brass, bronze, gun metal, steel or some other suitable material having strength. One end of the tube II is enlarged at 22. to take care of the larger diameter of the eye lens. The complete telescope is mounted on rifle barrel II by means of mounts 24 and II, in such a position that the right end of the telescope is at a'distance of approximately 5 inches from the proper position of the eye. As it will be readily observed from Fig-3. in this position the end of the telescope will readily clear the bolt action I. and thus may be mounted very close to the rifle barrel without interfering in any way with the proper operation of the rifle. In other words, the distance I! between the axes of rifle barrel 2! and of telescope 2| (Fig. 4) maybe very short so that short mounts I4 and 2| may be used providing a strong and stable mounting free from the danger of accidental displacements. Moreover, as it will be readily observed from Fig. 4, the rifle-sighting telescope embodying the invention will clear the bolt action of the rifle even if mounted in immediate proximity to the rifle barrel and having its axis p pendicularly above and in alignment with the axis of the rifle barrel, in contrast to priorv rifle-sighting telescopes which had to be mounted in a raised and/or oflE-set position.

The optical properties of my improved riflesighting telescope may be best seen from the following table of a preferred embodiment:

mm. Distance between eye lens and objective 252.4 Distance between eye lens and negative The lenses employed in the rifle-sighting telescope have the following properties:

Diameter Type Millimeters Eye lens 23 Compound positive. Negative lcns 16 Single negative. Erector system V 16 Compound positive. Objective 17. 5 D0.

properties:

Exit pupil 6.6 Magnification 2.5x Eye distance 124.5 mm.

Field 55' It will be noted that the rifle-sighting telescope embodying my invention provides a number 01' important advantages. Thus, my novel riflesighting telescope makes it possible for the first time in the historyof the art to provide eye distances over 4 inches.

, or accidentally changed under the most adverse operating conditions.

Moreover, the novel and improved rifle-sight ing telescope combines the advantage of increased eye distance with excellent optical properties, such as ample magnification and field which are A diaphragm having a diameter of at least equivalent to those of prior telescopes having inferior eye distances.

Furthermore, the novel rifle-sighting telescope may be manufactured in a simple and efiicient manner by means of existing manufacturing equipment without requiring any expensive changes.

Although the present invention has been described in connection with a preferred embodiment thereoflvariations and modifications may be resorted to by those skilled in the art without departing from the principles of the present invention. I consider all of these variations and modifications as within the true spiritand scope of the present invention asdisclosed in the present description and defined by the appended claims.

I claim:

1. In a lens system for rifle-sighting telescopes, the combination comprising an objective, an eye lens cooperating with said objective to produce an enlarged image, an erector system constituted of at least one erector lens interposed between said objective and said eye lens, a negative lens interposed between the erector system and the eye lens in proximity to the second focus of said erector lens, said negative lens being adapted to increase the eye distance of said lens system substantially without changing the field of view and the power of said lens system, and means for holding said lensesin predetermined operative position to form a compact and integral unit adapted to be mounted on a rifle barrel in such a position that the eye of the operator is in proximity to the firing chamber but at a distance therefrom sufiicient to positively eliminate the danger of injury from the recoil of the rifle.

2. In a lens system for rifle sighting telescopes, the combination comprising an objective, an eye lens cooperating with said objective to produce an enlarged image, an erector system constituted of at least one erector lens interposed between said objective and said eye lens, a negative lens interposed between the erector system and the eye lens substantially in the second focus of said erector lens, said negative lens being adapted to increase the eye distance of said lens system beyond '4" substantially without changing the field of view and the power of said lens system, and means for holding said lenses in predetermined operative position to form a compact and integrai unit adapted to be mounted on a rifle barrel in such a position that the eye of the operator is in proximity to the firing chamber but at a distance therefrom suflicient to positively eliminate the danger of injury from the recoil of the rifle.

FREDERICK L. G. KOLIMORGEN. 

